The advantages of water faucet valves having arcuate valve members with a spherical profile are well known in the art. Examples of such valves are disclosed in U. S. Pat. Nos. 3,056,418, issued Oct. 2, 1962; 3,417,783, issued Dec. 24, 1968 and 3,906,999, issued Sept. 23, 1975. Certain of such valves have achieved great commercial success due to their simplicity of design and ease of manufacture coupled with reliability of operation since such faucets do not utilize compression washers that have a tendency to wear relatively quickly and allow leakage. The arcuate valve member surfaces allow cooperation with mating, concave valve seats with a seal between the valve member and seat being provided by spring-loaded seals that utilize not only spring force but also the pressure of incoming water for sealing purposes.
Most commonly, arcuate valve members have been formed from brass. The forming operation first requires the formation of the desired arcuate profile, most commonly spherical, and then subsequent machining operations to provide either water passages through the valve or about the periphery of the valve. As readily may be appreciated, the relatively high price of brass and the necessity for such machining has constituted a substantial portion of the cost of manufacture of such faucets.
Various proposals have been considered in the past to mold arcuate valve members from synthetic plastic material, but such proposals have not proven wholly satisfactory because of the difficulty in molding the desired valve shapes and the inability of a moldable synthetic material available to wear well over the extended periods and high frequency of use to which commercial water faucets are subjected.
It is, therefore, an object of this invention to provide a water faucet of the arcuate valve member type wherein the valve member is a molded plastic element having a design that easily may be molded utilizing conventional techniques. A further object of the invention is to provide a water faucet having an arcuate, molded plastic valve member in which a provision is made for greater resistance to wear, especially against the necessary stops included in faucet designs to limit valve member movement to useful positions. A still further object of this invention is the provision of a water faucet having a molded plastic, wear resistant spherical valve member having overall simplicity of design, ease and low cost of manufacture and reliability of operation.